1. Field of the Invention
This invention relates to rotary burners of the type used in large industrial boiler and furnace installations to burn liquid and/or gaseous fuels.
2. Description of the Prior Art
Burners of the above-described type conventionally include a central bearing support surrounded by a somewhat cylindrical housing. These two components cooperate in a radially spaced relationship to define an annular housing chamber having axially aligned inlet and outlet openings. A shaft is journalled for rotation in bearings carried by the bearing support. The end of the shaft adjacent to the housing outlet opening has a hub which carries a plurality of hollow radially disposed driver arms. Conduits extend through the shaft and hub to carry gas and/or a mixture of oil and steam to the driver arms, the latter being provided with fuel discharge nozzles. As herein employed, the term "nozzle" is to be broadly construed to also encompass drilled orifices. The angular arrangement of the fuel discharge nozzles in relation to the shaft axis is such that the fuel exiting therefrom produces a reactive force which rotatively drives the shaft. The shaft is further provided with a fan. The fan operates during shaft rotation to produce a flow of combustion air which flows through the housing chamber through the inlet and outlet openings. The fuel being discharged from the nozzles of the rotating driver arms mixes with the exiting flow of combustion air and is then burnt in a combustion chamber.
Burners of the above-described type have been widely and successfully employed for many years. In some instances, however, their operation has been plagued by a premature burnout of certain component parts, particularly the shaft bearings and the hub supporting the radial driver arms. When such burnouts occur, the burner must be shut down for costly and time consuming repairs.
Over the years, various design modifications have been attempted in order to obviate this problem. Often, such modifications have entailed the use of exotic heat resistant alloys, which significantly increase the cost of the burners. While these attempts have been marginally successful, the problem has to a large extent remained unsolved.